1. Field of the Invention
The present invention relates generally to a sheet feed device that includes a first sheet cassette and a second sheet cassette disposed on the first sheet cassette, and selectively feeds sheets (recording media) that are positioned in the first sheet cassette or sheets that are positioned in the second sheet cassette and are different than, e.g., smaller than, the sheets in the first sheet cassette. The present invention also relates to an image recording apparatus having such a sheet feed device.
2. Description of Related Art
A sheet feed device used in a known image recording apparatus, such as a printer and/or a facsimile machine, is disclosed, for example, in Japanese Laid-Open Utility Model Publication No. 6-49439. In this known sheet feed device, the sheet cassette for accommodating a stack of recording media (such as recording sheets and cut sheets) is disposed in a lower side of the apparatus body (housing). A cover member covering a rear half of the sheet cassette is provided with a pair of guide holes elongated in the sheet feed direction, and the cover member is further provided on its upper surface with a pair of regulation plates for positioning the right and left sides of a manually fed sheet. A partition plate is disposed in an accommodating portion of the sheet cassette so as to divide a front opening into upper and lower spaces. A pair of levers projecting from the upper surface of a rear portion of the partition plate are fitted loosely in the pair of guide holes. A sheet feed roller is disposed above the front opening of the sheet cassette. With this device for recording an image on a manually fed sheet, a sheet is placed at a predetermined position of the partition plate, and the partition plate is moved forward so that its upper front portion is placed below the sheet feed roller. Thus, the sheet may be fed by the sheet feed roller. On the other hand, when the partition plate is moved backwards, the sheets stacked in the sheet cassette are fed one by one by the sheet feed roller in cooperation with a pair of separation pieces provided near the front corners of the sheet cassette.
Another sheet feeding device is disclosed in Japanese Laid-Open Patent Publication No. 11-59925. In this known sheet feed device, a sheet feed roller is disposed above the front end of a first sheet cassette. The first sheet feed cassette has a plate-like cassette base on which a stack of sheets are placed, and the cassette base is pushed up towards the sheet feed roller by a coil spring provided at the lower front portion of the cassette base. The cassette base is disposed between a pair of side regulation plates that are movable to contact and to position the right and left sides of the sheets in the first cassette. A plate-like second sheet cassette is detachably attached onto the cassette base. The second sheet cassette has fixed side regulation plates and a fixed rear end regulation plate that contact and position the sheets in the second sheet cassette. The sheets in the second sheet cassette are smaller in size than those in the first sheet cassette.
However, in the sheet feed device disclosed in Japanese Laid-Open Utility Model Publication No. 6-49439, because the partition plate does not include any separation pieces for separating one manually fed sheet from the other manually fed sheets, only a single, smaller-sized sheet, such as a postcard, is allowed to be placed on the partition plate. Consequently, in order to record an image on a plurality of postcards, it is necessary for the user to place one postcard at a time on the partition plate, and to move the partition plate back and forth, which is burdensome to the user.
Moreover, in the sheet feed device disclosed in Japanese Laid-Open Patent Publication No. 11-59925, although a plurality of smaller sized-sheets may be accommodated in the second sheet cassette, the second sheet cassette must be detached from the first sheet cassette when image recording is performed on larger-sized sheets. For example, when trial recording is performed on a plain sheet in the first cassette, in order to check the position and color conditions of a recorded image before actual recording on a postcard, the second sheet cassette must be detached from the first sheet cassette and then reattached to the first sheet cassette. In other words, it is not possible to feed sheets in the first sheet cassette that are different in size from those feed sheets in the second sheet cassette, in a state where the second sheet cassette is set in the first sheet cassette. Consequently, the user must attach and detach the second sheet cassette each time that the sheets to be used are switched, which is burdensome to the user.